Windows 11: Optional update comes with the bug in safe mode

The latest update KB5012643 for Windows 11 is not without its problems. Users are reporting that they have noticed issues with Safe Mode with the optional update released a few days ago. This doesn’t seem to be an intermittent problem but is reproducible with every attempt to boot in safe mode. Once the PC is started in safe mode, there is flickering and usability is severely limited.

Bug in UEFI/BIOS

The whole thing needs to be looked at critically, as Microsoft had actually announced that it would introduce an enhanced Secure Boot component with the update to Build 22000.652. At the moment one can only speculate, but the newly appeared error gives an idea that there is now a bug in the UEFI/BIOS.

Microsoft itself has not yet responded to the issue. In the known issues section, the Windows team currently reports only one bug related to recovery media created using the “Backup and Restore” app (Windows 7). Since this is an optional update, the easiest recommendation is to wait and not install KB5012643 yet. There is still plenty of time to find and fix the bug before it is distributed as a security update to all users on May 10.

According to Deskmodder, if you have already done the optional update and are now having problems in safe mode, you should press 5 or F5 instead of 4 or F4 when you start safe mode. “The network drivers are loaded via F5 and Windows 11 will start safe mode normally and with no flickering,” it says. The previous test in the Windows Insider program had not heard about the problem.